Nl'DIBRANCHIATE GASTEROPODA. 15 



seen a quite fine round pore (fig. 19 f). The spermatic duet entering at the base of the organ (fig. 20a), 

 became by and by a little thinner forward, and with its close windings it was to be traced through- 

 out to the pore on the point of the penis (figs 20, 19 fj. The short oviduct (fig. 19b) opened into 

 the uppermost part of the duct of the mucous gland. The spermatheca (fig. iSb) was formed like 

 a short bag, of a length of 2 cm , it was partly covered by the prseputium; its vaginal duct was a little 

 shorter than the seminal vesicle, by its short uterine duct hung by a short stalk the flat sperm a to- 

 cyst, covered by the spermatheca, empty like this, and about half as large. - The mucous gland 

 formed the chief portion of the whole anterior genital mass; hindmost on its under side was seen a 

 more separated, roundish, more whitish, flat part, of a diameter of ca. 2 cm , the foremost part of which 

 might without tearing be loosened from the rest of the mass. In the foremost and undermost part 

 of the mucous gland was found the long and high, compressed cavity of the organ, the foremost wall 

 of which was only thin, while the hindmost one was formed by the chief mass of the mucous gland, 

 the inside of which was yellowish, and showed several communicating cavities. The duct of the 

 mucous gland was short, only o'5 im long, with strong folds on the inside; the cleftlike outer aperture 

 was bordered bv the two above described genital folds, which below were only connected with each 

 other by a narrow commissure, and above by a very broad one (pi. I, fig. 2, 18 c). 



In itself is was scarcely probable that this deep-sea form from the Davis Strait could be 

 specifically identical with the earlier described form from the large depths in the middle of the Pacific. 

 We have also, in spite of considerable correspondences between the two forms, found not a few and 

 rather great differences. Among these differences were especially prominent the different colour of 

 the cavity of the mouth, another form of the mandibles, and a great difference in the structure of the 

 radula, the tooth-plates of which upon the whole were feebler and longer in this species, and the 

 median teeth especially had quite another form. 



Fam. Doridoxidae. Nov. fam. 



Forma corporis ut in Doridibus; sed branchia (dorsalis) nulla, et anus lateralis (non dorsalis). 

 Rhinophoria ut in Doridibus. 



Bulbus pharvngeus fortis, mandibulis anticis fortissimis armatus. Radula dente mediano forti, 

 pleuris multidentatis. 



We know cladohepatic nudibr auchiata in which the whole branchial apparatus with 

 its hepatic lobes has disappeared; such is the case in the Phylliroidae, Pleuroleuridae and Hedylidae 1 ). 

 And others are found, the Tritoniadae, in which the branchial apparatus has remained without the 

 hepatic lobes. It was almost to be expected that also among the holo hepatic nudibranchiata 

 forms without gills were to be found. And such a form we find in the below described new animal, 

 which is also distinguished from all other holohepatica by the anus not being situated dorsally, but 



'1 R. Bergh, Die Hedvliden, eine Familie der kladohepat. Nudibranchien. Verh. d. k. k. zool. bot. Ges. in Wien. 

 XLV. 1895. p. 1 — 12. Taf. I— II. 



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